6.0 US version of iphone4s Unicom can't send short messages online.

Cellular Data (Internet Settings)

Access point (APN): 3gnet

User name: empty

Password: empty

If you can't send SMS, you may need to set the SMS center number:

1. Delete SMS center number: dial ##5005*7672# with iPhone.

2. Set SMS center number: dial *5005*7672*+86 SMS center number # with iPhone;

When using the internal command, first use the delete command, and then set the SMS center number.

Note: The set SMS center number is generally similar to the mobile phone number after +86. You can call the local phone number 100 10 to get it.